This is probably a very simple problem for most. I created a slideshow and I need for it to replay automatically. I set loop playback, then rendered. I created the DVD in DVD Architect and it plays once and quits.

What setting do I need to set to allow automatic replay?

In DVDA goto the project properties and set the END ACTION to point back to the slideshow. Harder to explain than to do so once you get to END ACTIONS it should jump right out at you.
One thing though before you open END ACTIONS make sure to open the projcect on the timeline in DVDA. Double click on the play button if you have a menu OR if single play then the project is already on the timeline so you're good to go. After that then goto END ACTIONS and you'll see the option you need.

Just like Don said:

1. Don't set loop properties in Vegas, has nothing to do with DVDA.

2. Open DVDA. Is the DVDA project with a menu? If so, double click on the title of the movie.

3. On the upper right hand side is the Media Properties Box.

4. Click on End Actions

5. You will see below that Destination Item. to the right of Desination Item will be another box, click on that to activate it, and you should see a drop down box.

6.when the drop down box opens, click on Loop Point.

Save your project, then preview it and make sure it works the way you want before burning.

Thanks guys. Got it working. This was for a 55th year anniversary for my in-laws to be displayed during the party. Now I won't be in the dog house with my wife!

That would be a very bad place to be. Trust me I know. :-(
Anyway glad we could help.

Just for future reference... I've seen many people do this simply by pressing the "Repeat" button on the DVD player! When I was doing this type of thing regularly, I always used End-Actions as well.